Cold water curable orthopedic cast

Claim 2

A bandage material for forming in place an orthopedic cast comprising a pliant, large mesh fabric carrier formed from a knot of a high-strength, high-modulus yarn with a low mixture pick-up, the fabric carrier having openings of relatively large transverse dimension, and being coated with a polymer composition comprising (a) a cold water curable polyurethane prepolymer comprising the reaction product of a polyalkylene ether diol, a polyalkylene ether triol and a diisocyanate, wherein the ratio of diol to triol is from 1:9 to 9:1 and (b) an amine catalyst not bound into the prepolymer until formation of the bandage, thus allowing for a more homogeneous cure of the prepolymer.

Claim 3

The bandage material according to claim 1, wherein the polymer composition further comprises a mineral acid.

Claim 4

The bandage material according to claim 2, wherein the mineral acid is phosphoric acid.

Claim 5

The bandage material according to claim 1, wherein the amine catalyst is a tertiary amine.

Claim 6

The bandage material according to claim 4, wherein the tertiary amine is [(CH 3 ) 2 NCH 2 CH 2 ] 2 O.

Claim 7

The bandage material according to claim 1, wherein one equivalent of polyol (diol and triol) is reacted with more than 1.8 equivalents of isocyanate.

Claim 8

The bandage material according to claim 1, wherein the polyurethane prepolymer comprises the reaction product of polypropylene ether diol, polypropylene ether triol and a diisocyanate.

Claim 9

The bandage material according to claim 7, wherein the diisocyanate is a modified diisocyanate prepared by reacting a diisocyanate with less than a stoichiometric amount of carbodiimide.

Claim 10

The bandage material according to claim 8, wherein the modified diisocyanate is a mixture of OCN--R--NCO, and ##STR6## where R is ##STR7##

Claim 11

The bandage material according to claim 1, wherein the yarn is comprised of a plurality of filaments.

Claim 12

The bandage material according to claim 10, wherein the yarn is of 400-1,500 denier.

Claim 13

The bandage material according to claim 11, wherein the yarn is of 500-1,500 denier.

Claim 14

The bandage material according to claim 12, wherein the yarn is of 840-1,000 denier.

Claim 15

The bandage material according to claim 1, wherein the yarn is a polyester.

Claim 16

The bandage material according to claim 14, wherein the polyester is polyethylene terephthalate.

Claim 17

The bandage material according to claim 1, wherein the fabric carrier comprises a Raschel type knit.

Claim 18

The bandage material according to claim 16, wherein the fabric carrier is comprised of walewise parallel chains and filling threads having sinuous configurations looped between said chains, said fill thread loops being formed around a link of one of said chains and then around a link of another of said chains, each loop of each fill thread being in a course different from the course in which the other looping thereof occurs and the loops of different fill threads in the same course pointing in the same direction, said fabric being substantially unstretchable in the walewise direction, but substantially stretchable in the direction normal thereto, the fabric containing not more than 20 wales per inch width, and not more than 25 courses per inch length, the weight of fabric being 0.025-0.090 lbs/linear yard.

Claim 19

The bandage material according to claim 1, wherein the openings of the fabric carrier are 0.015-0.25 sq. in.

Claim 20

The bandage material according to claim 18, wherein the openings of the fabric carrier are 0.022-0.050 sq. in.

Claim 21

The bandage material according to claim 1, wherein the polymer composition further comprises a thixotropic agent.

Claim 22

The bandage material according to claim 20, wherein the thixotropic agent is fumed silica.

Claim 23

The bandage material according to claim 1, wherein the polymer composition further comprise a defoamant.

Claim 24

The bandage material according to claim 22, wherein the defoamant is a silicone-based defoamant.